git-describe - Give an object a human readable name based on an available ref
git describe [--all] [--tags] [--contains] [--abbrev=<n>] [<commit-ish>...]
git describe [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]
git describe <blob>
The command finds the most recent tag that is reachable from a commit. If the
tag points to the commit, then only the tag is shown. Otherwise, it suffixes
the tag name with the number of additional commits on top of the tagged object
and the abbreviated object name of the most recent commit. The result is a
"human-readable" object name which can also be used to identify the
commit to other git commands.
By default (without --all or --tags) git describe only
shows annotated tags. For more information about creating annotated tags see
the -a and -s options to git-tag(1).
If the given object refers to a blob, it will be described as
<commit-ish>:<path>, such that the blob can be found at
<path> in the <commit-ish>, which itself describes
the first commit in which this blob occurs in a reverse revision walk from
Commit-ish object names to describe. Defaults to HEAD if
Describe the state of the working tree. When the working
tree matches HEAD, the output is the same as "git describe HEAD". If
the working tree has local modification "-dirty" is appended to it.
If a repository is corrupt and Git cannot determine if there is local
modification, Git will error out, unless ‘--broken’ is given,
which appends the suffix "-broken" instead.
Instead of using only the annotated tags, use any ref
found in refs/ namespace. This option enables matching any known
branch, remote-tracking branch, or lightweight tag.
Instead of using only the annotated tags, use any tag
found in refs/tags namespace. This option enables matching a
lightweight (non-annotated) tag.
Instead of finding the tag that predates the commit, find
the tag that comes after the commit, and thus contains it. Automatically
Instead of using the default 7 hexadecimal digits as the
abbreviated object name, use <n> digits, or as many digits as needed to
form a unique object name. An <n> of 0 will suppress long format, only
showing the closest tag.
Instead of considering only the 10 most recent tags as
candidates to describe the input commit-ish consider up to <n>
candidates. Increasing <n> above 10 will take slightly longer but may
produce a more accurate result. An <n> of 0 will cause only exact
matches to be output.
Only output exact matches (a tag directly references the
supplied commit). This is a synonym for --candidates=0.
Verbosely display information about the searching
strategy being employed to standard error. The tag name will still be printed
to standard out.
Always output the long format (the tag, the number of
commits and the abbreviated commit name) even when it matches a tag. This is
useful when you want to see parts of the commit object name in
"describe" output, even when the commit in question happens to be a
tagged version. Instead of just emitting the tag name, it will describe such a
commit as v1.2-0-gdeadbee (0th commit since tag v1.2 that points at object
Only consider tags matching the given glob(7)
pattern, excluding the "refs/tags/" prefix. If used with
--all, it also considers local branches and remote-tracking references
matching the pattern, excluding respectively "refs/heads/" and
"refs/remotes/" prefix; references of other types are never
considered. If given multiple times, a list of patterns will be accumulated,
and tags matching any of the patterns will be considered. Use
--no-match to clear and reset the list of patterns.
Do not consider tags matching the given glob(7)
pattern, excluding the "refs/tags/" prefix. If used with
--all, it also does not consider local branches and remote-tracking
references matching the pattern, excluding respectively
"refs/heads/" and "refs/remotes/" prefix; references of
other types are never considered. If given multiple times, a list of patterns
will be accumulated and tags matching any of the patterns will be excluded.
When combined with --match a tag will be considered when it matches at least
one --match pattern and does not match any of the --exclude patterns. Use
--no-exclude to clear and reset the list of patterns.
Show uniquely abbreviated commit object as
Follow only the first parent commit upon seeing a merge
commit. This is useful when you wish to not match tags on branches merged in
the history of the target commit.
With something like git.git current tree, I get:
[torvalds@g5 git]$ git describe parent
i.e. the current head of my "parent" branch is based on
v1.0.4, but since it has a few commits on top of that, describe has added
the number of additional commits ("14") and an abbreviated object
name for the commit itself ("2414721") at the end.
The number of additional commits is the number of commits which
would be displayed by "git log v1.0.4..parent". The hash suffix is
"-g" + 7-char abbreviation for the tip commit of parent (which was
2414721b194453f058079d897d13c4e377f92dc6). The "g" prefix
stands for "git" and is used to allow describing the version of a
software depending on the SCM the software is managed with. This is useful
in an environment where people may use different SCMs.
Doing a git describe on a tag-name will just show the tag
[torvalds@g5 git]$ git describe v1.0.4
With --all, the command can use branch heads as references, so the
output shows the reference path as well:
[torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
[torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^
With --abbrev set to 0, the command can be used to find the
closest tagname without any suffix:
[torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
Note that the suffix you get if you type these commands today may
be longer than what Linus saw above when he ran these commands, as your Git
repository may have new commits whose object names begin with 975b that did
not exist back then, and "-g975b" suffix alone may not be
sufficient to disambiguate these commits.
For each commit-ish supplied, git describe will first look for a tag
which tags exactly that commit. Annotated tags will always be preferred over
lightweight tags, and tags with newer dates will always be preferred over tags
with older dates. If an exact match is found, its name will be output and
searching will stop.
If an exact match was not found, git describe will walk
back through the commit history to locate an ancestor commit which has been
tagged. The ancestor’s tag will be output along with an abbreviation
of the input commit-ish’s SHA-1. If --first-parent was
specified then the walk will only consider the first parent of each
If multiple tags were found during the walk then the tag which has
the fewest commits different from the input commit-ish will be selected and
output. Here fewest commits different is defined as the number of commits
which would be shown by git log tag..input will be the smallest
number of commits possible.
Tree objects as well as tag objects not pointing at commits, cannot be
described. When describing blobs, the lightweight tags pointing at blobs are
ignored, but the blob is still described as <committ-ish>:<path>
despite the lightweight tag being favorable.